1. Field of the Invention
The present invention relates to an electronic display measuring device which incorporates an encoder which is adapted to convert a variable into an electric signal and which further has an electronic display for displaying a measured value in digital and/or analog form. The present invention may be applied to general measuring devices such as length measuring devices, e.g., dial gauges and slide calipers, which are equipped with electronic displays, as well as weight, temperature and speed measuring devices.
2. Description of the Prior Art
One type of measuring device for measuring length, thickness, width, weight, speed and the like has heretofore been known in which, as shown in FIG. 10, the movement of a spindle 51 which is slidably provided on the main body is detected through a sensor 52 and converted into an electric signal by an encoder 53 incorporated in the main body, and a measuring factor is specified by a switch 54 through a controller 55, thus displaying a measured value on an electronic display 56 in analog and/or digital form. This type of measuring device has various advantages such as a high degree of measuring accuracy and an ease of reading and has therefore been widely applied.
In the above-described type of conventional measuring device, a large number of switches are provided for the purpose of obtaining maximum, minimum and mean values of measured values, clearing and holding a displayed value, changing the expression of units between inch and millimeter and turning on/off a power supply, and the number of switches is increasing with an increase in number of functions of this type of measuring device.
On the other hand, as the range of their application enlarges, measuring devices are demanded in these days to have reduced sizes so as to be used as portable or inprocess devices. Such demand is sufficiently met with respect to built-in elements such as encoders owing to the development of electronic technology, but reduction in size of switches is disadvantageously limited to a certain extent. More specifically, in view of the size of operators' fingers and operability, switches 57 need to have a certain size and it is necessary to provide a large number of switches 57 in the vicinity of a display and, particularly, on the same plane as a display screen 58, as shown in FIG. 11, which means that the size of a measuring device 59 as a whole is determined by the number and size of switches 57. On the other hand, if the overall size of the device 59 and the size of each switch 57 are limited, the area for the display screen 58 is restricted, and this leads to various problems: namely, it becomes difficult to read a measured value; it becomes impossible to simultaneously display various kinds of data; and it is difficult to additionally provide functions which enable display of an index, measuring procedure, decision of pass-fail judgement, etc. Accordingly, the prior art involves the problem that the existence of switches disadvantageously limits the size of the display screen on the main body.